In this paper, the multiple scattering of obliquely incident elastic waves from fibers encased in a solid viscoelastic medium is studied. This problem has applications in ultrasonic nondestructive testing of composite materials. The fibers could be either isotropic or transversely isotropic. Based on the existing theory of elastic wave scattering from a single fiber, a mathematical model for multiple scattering of elastic waves from a number of parallel fibers embedded in a viscoelastic matrix is derived. This model incorporates all three kinds of longitudinal, horizontally polarized shear, and vertically polarized shear waves. The incident wave angle is arbitrarily chosen and the receiver can be considered to be at any desired location in space. The model is capable of handling any order of scattering from any number of cylinders. To validate the numerical results, a number of experiments were conducted on steel cylinders embedded in a polymeric block. With the aid of an ultrasonic probe, the scattered field was measured and analyzed. Comparing the analytical and experimental results, good agreement was observed between resonance frequencies observed in experiments and mathematical model

Keywords: Multiple scattering, Fiber reinforced composite, Transversely isotropic fiber, Viscoelastic material

Full-Text [PDF 853 kb]   (4835 Downloads)